package tree;

/**
 * @Author: suruomo
 * @Date: 2020/8/24 15:52
 * @Description: 617 合并二叉树
 */
public class MergeTree {
    public class TreeNode{
        int val;
        TreeNode left;
        TreeNode  right;
        TreeNode(int x){
            val=x;
        }
    }
    public TreeNode mergeTrees(TreeNode t1, TreeNode t2) {
        if (t1==null&&t2==null){
            return null;
        }
        if (t1==null&&t2!=null){
            return t2;
        }
        if (t1!=null&&t2==null){
            return t1;
        }
        t1.val += t2.val;
        t1.left = mergeTrees(t1.left, t2.left);
        t1.right = mergeTrees(t1.right, t2.right);
        return t1;
    }
}
